Thin-Client to connect and use virtual-machines on a server

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I’m looking for an infrastructure which ideally should be maintained as following:
Several (virtual) operating-systems (linux and windows as well) should run on a server simultaneously and be accessible over the local network from heterogeneous clients (such as linux, os x and windows operating systems running on a desktop computer).
The aim is that it doesn’t matter which client device in the local network you use, you can always connect and use these operating-systems on the server. It should also be possible to use on the client device two or three operating-systems from the server at
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Stories similar to Thin-Client to connect and use virtual-machines on a server

I am working on a project for my operating systems class. I'm having difficulty fulfilling 2 requirements for it. It asks for 5 network configurations for Ubuntu Gnome and what client/server operating system can connect with Ubuntu Gnome.

For the 5 network configurations, would it be something like what this link has?

Hello folks,
This is the scenario: You are the admin of a network which has a central server and client PCs. The clients have no operating systems installed. The server contains all OS images that the clients need.

A client will load one of the OS images from the server via network to use. After the client shutdowns, the OS on the client is gone too, no installation needed.